Fix planner's test for case-foldable characters in ILIKE with ICU.
As coded, the ICU-collation path in pattern_char_isalpha() failed
to consider regular ASCII letters to be case-varying. This led to
like_fixed_prefix treating too much of an ILIKE pattern as being a
fixed prefix, so that indexscans derived from an ILIKE clause might
miss entries that they should find.
Per bug #15892 from James Inform. This is an oversight in the original
ICU patch (commit eccfef81e), so back-patch to v10 where that came in.
Discussion: https://postgr.es/m/15892-e5d2bea3e8a04a1b@postgresql.org
Branch
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master
Details
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https://git.postgresql.org/pg/commitdiff/03c811a483b243952874d8e2b3f0c2e3793bc952
Modified Files
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src/backend/utils/adt/like_support.c | 8 +++---
src/test/regress/expected/collate.icu.utf8.out | 35 +++++++++++++++++++++++++-
src/test/regress/sql/collate.icu.utf8.sql | 12 ++++++++-
3 files changed, 50 insertions(+), 5 deletions(-)